Furnace for treating metals.



No. 718,760. PATENTED JAN. 20, 1903; I

H. D. HIBBARD. FURNACE FOR TREATING METALS;

APPLICATION FILED FEB. 18, 1901.

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No. 718,760. PATENTED JAN. 20, 1903. H. D. HIBBARD.

FURNACE FOR TREATING METALS.

APPLICATION FILED FEB. 18, 1901. no MODEL. I a SHEETS-SHEET 2.

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particularly with reference to its use in car- UNTTED STATES HENRY D. HIBBARD, OF P FURNACE FOR TR LAINFIELD, NEW JERSEY.

EATING METALS.

SFZEGIFIGATION forming part of Letters Patent No. 718,760, dated January 20, 1903.

Application filed February 18, 1901. Serial No. 47.832. (N0 model- To all whom it ntcty concern:

Be it known'that I, HENRY D. HIBBARD, a citizen of the United States of America, residing in Plainfield, in the county of Union, State of New Jersey, have invented an Improved Furnace for Treating Metals, of which the following is a specification.

My improved furnace has been designed primarily for carrying out in an economical, efficient, and convenient Way the process of treating metals set forth in my Letters Patent No. 669,925, dated March 12, 1901. In that patent there is set forth a mode of toughening manganese steel articles consisting in establishing in a heating apparatus a series of consecutive heating zones having temper atures gradually increasing from one zone to another, from the cool to the hot end of the furnace, introducing the articles first into the zone of lowest temperature and moving them through the consecutive zones, so as to subject them to a gradually-increasing temperature, preventing the products of combustion from coming into contact with the articles in the zones of lower temperature, but permitting them to come into contact therewith during their passage through the hottest zone, and finally withdrawing the articles from this hottest zone and plunging them into a coolingbath.

I will describe my improved furnace more rying out the process referred to; but it should be understood that my improvements are also applicable to other uses-as, for instance, the treatment of armor-plate and other kinds and forms of metal.

In the accompanying drawings, Figure 1 is a vertical longitudinal section on the line 1 1, Fig. 2, through the furnace. Fig. 2 is a sectional plan on the line 2 2, Fig. 1. Fig. 3 is a transverse section on the line 3 3, Figs. 1 and 2. Fig. 4 is an enlarged sectional view on the line 4 4, Fig. 3. Fig. 5 is an enlarged plan view of one of the traveling sections. Fig. 6 is a perspective view of one of'the removable slats, and Fig. 7 is an enlarged view of a detail.

The main body of the furnace consists of an elongated heating-chamber A, having openings a, a at its opposite ends, closed by sliding doors B B. Near the outlet end B is the fireplace or other source of heat E, and at the same end, but on the opposite side of the heating-chamber, I arrange the outlet flue or fiues leading to the chimney C, which in this case is shown as erected on the same side of the furnace as the fireplace E. It is this end of the furnace which is to be heated to the highest temperature required for the operation, while the other end of the chamber, at which the articles are first admitted, will be comparatively cool, and the consecutive heating zones will have temperatures increasing from one zone to another from the cool to the hot end of the furnace. In the drawings I have shown two outlet-fiues E and E leading down to a common cross-flue 6, Figs. 2 and 3,.opening into the bottom of the chimney O.

Besides'the end doors B and. B, I employ intermediate sliding partitions P P P to aid in regulating the temperature in different parts of the furnace. In this instance I have shown three such partitions, which can be raised and'lowered and which in their lowered positions may not reach down to the floor of the heating-chamber, but leave spaces p for the passage of air currents under the partitions drawn by the chimney-draft through openings closable by slides 13 in the parts of the roof or walls between the partitions. I prefer to make the partition P which is next to the hot end of the furnace, and also the outlet-door B, fireproof. All these partitions and the two doors at the opposite ends of the heating-chamber may be suspended from arms or counterweighted levers D adapted to turn upon a horizontal shaft D, mounted in brackets 61 on the structure of the furnace, Figs. 1 and 3. As shown in Fig. 7, each lever is connected to the shaft by a lost-motion device, as by a spline or key It on the shaft, working in a slot or recess is on the lever, so that while any one of the levers may be turned on the shaft in the direction of the arrows, Fig. 9, to raise its own partition or door without disturbing any of the other partitions or doors, yet by turning the shaft D, as by means of an independent lever D Fig. 1, all the partitions and doors may be elevated at once.

The bottom or floor of the heating-chamber is formed by a series of sections F, which are unattached to each other, but are closely adjoinedthat is, in close contact end to end so as to make a closed bottom for the heatingchanlber. Each section has large and numerous holes through it, or, in other words, is an open-work grid; but such open-work is adapted to have its surface closed and provided with a protective refractory covering, which is easily removable. Each section has on its under side longitudinal ribs fto run on slides or antifriction-bearings, such as rollers carried by endless chains G, which pass over wheels H at opposite ends of and outside the furnace, Fig. 1. These roller-chains in turn are supported upon longitudinal rails J, carried by brackets J on the bottom of the furnace, the return stretch of the roller-chain passing underneath, preferably through these brackets, and running on rails J as illustrated in Fig. 4. The preferred construction of these grids or sections will be best understood on reference to Fig. 5, where each section is shown as consisting of a rectangular open frame with vertical longitudinal ribs f and cross-ribs f The longitudinal ribsf have flanges f near their upper edges, forming grooves near the surface of the section to receive and support the covering slats or plates M, which may be inserted from the end to close up the surface of the section or grid. These plates M may be suitably constructed so that by application of a tool they may be easily and quickly withdrawn from the grids, and for this purpose I prefer to provide each plate with a hole m near one end, so that a hooked tool may be inserted by a workman to draw out the plates from the end of the grid at the proper time. The upper surface of the rib constituting the advance side of the grid has in this case notches m Fig. 5, for the passage of the nose of the inserted hook in withdrawing the plates. The purpose of closing up the surface of the openwork grid or section is to arrange upon it a protective coating of refractory materialsuch as sand or fire-brick, or bothand the purpose of making this closing means removable is to be able to get rid of this protective coating where desirable immediately after the section carrying the metallic articles under treatment has come out of the furnace, so that when the section and the metallic articles thereon are then plunged together into the liquid in the cooling-tank the liquid can circulate freelyaround and under the articles on the section. I prefer to construct the successive sections so as to close the joints between them in the furnace by providing on the forward end of each section an overlapping fiange n to fit into a recess n at the back of the section in advance of it. As shown in Fig. 4, it is preferable to build the furnace with offsets a, to overlap the surfaces of the sections at their edges, so that with the aid of the same the joints may be closed there.

Any suitable means may be provided for pushing the sections through the furnace. A

handling the sections and the metallic articles thereon. For this purpose I prefer to provide cranes, as indicated in Fig. 2. Near the inlet end of the furnace there may be a crane S, turning on a center .9 and having a sweep such as indicated by dotted curve :20, so as to conveniently transfer the grid or section, loaded or not, onto the chain-rollers at the entrance end of the furnace from any point within the range of the crane. A crane S, turning on the center 3 near the exit or discharge end of the furnace, may have a sweep such as indicated by dotted line 00, so as to convoniently lift a section and its charge olf the chain-rollers at the delivery end of the furnace and quickly lower them into the cooling-tank T and afterward transfer the section again to another point farther on,where it may be unloaded, the empty sections being deposited at a point between the two cranes.

The operation of the above-described apparatus in carrying out the process of toughening manganese-steel articles as before mentioned will be as follows: The articles to be treated will be loaded onto successive sections, either before or after the grids have been deposited by the crane S on the roller-chains at the entrance end of the furnace. If the articles to be treated are small,and therefore do not require any special care to provide for circulation of heat under them, the surface of the grid or section may be protected by refractory bricks laid over the grid,with or without the use of the removable slides M; but if the articles to be treated are relatively large it is important that they should be so supported upon the grid-sections that the prodnets of combustion can circulate under them and that when the grid and the metal articles thereon are deposited in the cooling-tank the water may freely circulate under and around the metal articles there. In such case I put the slides m in place and arrange on the grid-sections at intervals, as where the ribs f f cross each other, refractory bricks r, Figs. 4 and 6, and then spread over the grids m between the bricks a protective coating of granular refractory material, such as sand 0", not reaching to the top of the bricks. The metallic articles are then placed on the bricks and the section is ready to be shoved into the furnace. The sections are gradually pushed through the furnace with an intermittent movement as each successive grid-section is shoved in. The doors and partitions are raised together for each forward movement of the line of charged sections; but the intermediate partitions can be lifted and adjusted to any desired position independentlyof each other to regulate the heat in the several heating zones as the operator may consider required by the circumstances of the case and by the articles under treatment. As a loaded section emerges from the discharge end of the furnace workmen draw out from the end of the section the slides M to allow the sand to drop away, and at the same time other workmen attach the hoisting-tackle of the crane S to the sides of the section, which then, with the metallic articles upon it, is lifted off the roller-chains and quickly transferred to and deposited in the cooling-tank 'l, where owing to the removal of the sand or other refractory protective casting the water or other liquid can get access to practically all parts of the metallic articles, the bottoms as well as the sides and tops. It is not necessary in all cases that the bottom sections should all have holes in them. For instance, in starting the furnace it may be desirable to fill the heatingchamber first with uncharged sections, which will serve to protect the metal-work below, and so, also, at the close of a run it may be desirable to push in uncharged sections for the same purpose as the loaded sections are removed at the exit end. Such blank sections may be simple brick-covered plates. Such brick-covered sections may also be used in treating small castings. From the tank T, Fig. 2, the section with the articles thereon is lifted outand transferred to a suitablepoint where the cooled articles can be removed.

Among the advantages of my invention I may mention that it enables me to secure a large output, continuous operation, and economy of fuel and of-labor. Italso enables me to produce articles of improved quality, because they are not too suddenly heated, and I can get a better toughening effect, because the ent used. Again, weak articles may be properly supported on the bottom sections, so that when they are weakened by the heat they will not be thereby damaged or changed in shape, since they need not be touched in removing them (on the bottom section) from the furnace to the bath. Articles which are liable to warp in the furnace or bath can, in charging, be so bound to the bottom section that the latter will aid in preserving their shape.

I claim as my invention- 1. A furnace for treating articles of metal, comprising an elongated heatingchamber having near one end at one side a heating means and at the same end on the opposite side an outlet-flue for the products of combustion, and aplurality of partitions between said hot end of the furnace and its opposite end, said partitions being movable into and out of the path of the charge, whereby a series of consecutive heating zones maybe obtained having temperature gradually increasing from zone to zone without interfering with the passage of the charge, as and for the purpose described.

2. A furnace for treating articles of metal provided with an elongated heating-chamber having a heating means near one end, doors at the opposite ends of the heating-chamber, a series of movable partitions between the hot end of the heating-chamber and its opposite end and means whereby the doors and partitions maybe moved together or individually, substantially as described.

. 3. A furnace for treating articles of metal,

comprising an elongated heating-chamber having a heating means at one end and an outlet for the products of combustion near the same end, with movable partitions between said hot end of the furnace and the other end, said partitions not reaching to the floor of the heating-chamber, and air-inlets into the portions of the heating-chamber beyond the partitions, as and for the purpose described.

4. A furnace for treating articles of metal, having a heating-chamber with a movable bottom, said bottom having a covering of removable refractory material and means whereby said refractory material can be quickly removed while the articles are supported by the bottom.

5. A furnace for treating articles of metal, having an elongated heating-chamber with a movable bottom,consisting of unattached but closely-adjoined sections, covered with removable refractory material, and means whereby said refractory material can be quickly removed while the articles are supported by the bottom.

6. A movable bottom forafurnace for treating articles of metal, said bottom having a covering of granular refractory material, and means whereby the said covering may be quickly removed while the articles are'supported by the bottom.

7. A movable bottom for a furnace for treating articles of metal, said bottom having a covering of refractory material, and means for quickly removing said refractory covering while the articles are supported by the bottom.

8. Afurnace for treating articles of metal, having an elongated heating-chamber provided with a movable bottom in sections, in

combination with chains carrying rollers, said chains extending beyond the furnace at both ends and rails and wheels supporting the chains.

9. In a furnace for treating articles of metal, a heating-chamber with a movable bottom in unattached sections having a removable refractory face-covering, means for quickly removing said covering while the articles are supported by the bottom, and means whereby the said sections may be moved together through the heating-chamber.

10. A furnace for treating articles of metal, comprisingan elongated heating-chamber, a

heating means at one end and an outlet for the products of combustion near the same end, a movable bottom in unattached sections covered with removable refractory material, means for quickly removing said covering while the articles are supported by the bottom and means for forcing the sections together through the heating-chamber from the cool, to and through the hot, end of the furnace, substantially as described.

11. A furnace for treating articles of metal, having an elongated heating-chamber provided with a movable bottom in sections covered with removable refractory material, means for quickly removing said covering while the articles are supported by the bottom, and means outside the furnace forpushing the sections through the furnace, as new sections are added at the charging end.

12. A furnace for treating articles of metal, having a movable bottom, said bottom being provided with open spaces through it adapted for the passage of refractory material and movable means for closing such spaces to support refractory material thereon.

13. A furnace for treating articles of metal, having an elongated heating-chamber, provided with a movable bottom in sections, each section covered with refractory material and means for quickly removing said refractory material from some of the sections, while the articles are supported by the sections, at the end of the heating operation.

14. A section for the movable bottom of a furnace, said section having open spaces through it adapted for the passage of refractory material, movable closing means for said open spaces and a refractory covering, as an( for the purpose described.

15. A section for the movable bottom of a heating-furnace, said section being an open metallic grid with longitudinal grooves near its surface, in combination with removable slides to fit the grooves and close the openings through the grid.

16. An open-work bottom to support articles to be treated in a furnace, said bottom having a covering of refractory material and means whereby the said covering may be quickly removed through the open-work at a the end of the heating operation,substantially as described.

17. An open-work bottom to support articles to be treated in a furnace, said bottom having a covering of granular refractory material and means whereby the said covering may be quickly removed through the openwork at the end of the heating operation, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

HENRY D. HIBBARD.

Witnesses:

I-IUBERT HOWSON, F. WARREN WRIGHT. 

